Blood clotting is critical to maintaining life, but dysfunctional clots can be fatal

Seven things you might not know about blood

The red stuff currently pumping throughout your body is a type of connective tissue that is both a solid and a liquid. The liquid portion—plasma—acts as a carrier for the solid portion, which includes blood cells and their biological brethren. Your body is constantly refreshing its supply of blood, creating new cells to replace those that have expired or died. This article overviews some lesser-known facts about blood (and why it's not always red).

Bears have evolved natural mechanisms to avoid blood clots while hibernating

Movement is essential to keeping blood from clotting, which raises the question of why animals such as hibernating bears don't suffer from clots despite going months lying still. New research suggesting that the animals may have evolved to have lower concentrations of a specific protein may explain this phenomenon.

'Buffy coats': The 1% of blood that helps fight off disease

When blood is centrifuged, white blood cells and platelets form a layer called the buffy coat between the plasma and red blood cells. This layer makes up less than 1% of blood, but its heightened leukocyte concentration makes it useful for toxicology research.

See how the Ebola virus affects blood circulation in the human body

Ebola infects and disables immune cells, causing a cascade of events that result in small blood clots throughout the body, weakening blood vessels, and interrupting blood flow to key organs.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Mosquito saliva acts as an anticlotting agent

The bug's piercing mouthpart, the proboscis, is actually several tubes—one for sucking, one for spitting. But the chemicals in its spit actually help its blood meal to flow, combating its victim's ability to clot at the puncture site.

Adhesion molecules and intercellular junctions allow cells to connect together

While some organic structures are mostly composed of non-cellular components (e.g., collagen and calcium phosphate minerals in bones), tissues and organs composed of connected cells rely on specialized proteins and connections to create watertight seals that protect cells within the interior from environmental molecules.

Hemorrhagic strokes make up roughly 13% of stroke events

A hemorrhagic stroke occurs when a faulty blood vessel within the brain bleeds. Though this is less common than an ischemic stroke, it is often far more deadly. This in-depth resource from the American Stroke Association provides a comprehensive overview of the two main subtypes of hemorrhagic stroke along with a useful animation of the condition.

Why vascular dementia develops

This type of dementia, the second most common form after Alzheimer's, develops due to microscopic bleeds and blood vessel blockages in the brain. The condition isn't curable but medications to help with blood clotting and high blood pressure are part of a suite of interventions designed to minimize damage to the brain.

How tPA, which helps dissolve blood clots, can lessen the severity of a stroke

One of the most exciting recent advances in treating stroke is a medication known as tissue plasminogen activator, or tPA. It is only effective for use in some ischemic strokes, and it must be delivered within 4.5 hours of symptom onset to have a chance at working.

Programmed cell death drives leaves to fall from trees

All living things have innate mechanisms to prompt organized cell death, typically to protect the integrity of the living organism. Leaves fall from trees to allow the tree to preserve resources and bloom again in the future.

Cells become cancerous if checkpoints in the cell cycle are damaged

Before cells divide, a protein called p53 can halt the cell cycle if damaged DNA is identified, preventing the fault from propagating to daughter cells. If p53 and other tumor-suppressing molecules cannot function due to mutations or other instabilities, damage can accumulate over successive generations until nothing stops cells from dividing uncontrollably, creating tumors.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Open brain surgery is not required for BCIs inserted via blood vessel injection

Synchron's brain-computer interface, the Synchron Switch, takes advantage of preexisting medical devices, such as stents and catheters. Cells grow over the device over a 90-day period, incorporating it into the vessel wall and minimizing clots.

What do vitamins actually do?

Vitamins are molecular tools the body needs to carry out regular cellular processes, such as wound healing. This 45-minute video dives into the science behind vitamins and their role in the body. There are 13 essential vitamins that must be...

The marvels of mucus

Mucus—otherwise known as snot or phlegm—has a gross reputation, but the substance is actually of vital importance, lining the moist surfaces of our nose, intestines, lungs, and more. It plays a constant role in keeping our tissues from drying out and acts as a line of defense, but if it gets too sticky or thick, it can cause problems. Read about the marvels of mucus here.

Autoimmunity is when the body attacks itself, causing inflammation

Inflammation is the body's way of healing itself, and acute inflammation saves our lives when we have injuries or infections. It increases blood flow to the affected areas to bring immune cells to fight off invaders. This often results in short-term swelling, redness, and pain.

Explore how the placenta acts as lungs, kidneys, and more in the womb

This temporary organ, formed from maternal and embryonic tissue, ultimately attaches to a fetus via the umbilical cord. It transports nutrients, oxygen, antibodies, and more from the mother to the developing fetus. It also carries carbon dioxide and waste away from the fetus. The placenta—which forms only during pregnancy—is expelled during childbirth, or it needs to be removed to prevent toxic maternal infections and extreme blood loss.

Why does the body have a stress response?

When encountering a stressful situation, the human body typically goes into what is known as "fight-or-flight" mode. Because it evolved as a survival mechanism, the biochemical response enables people and other mammals to react quickly to life-threatening situations. The carefully orchestrated yet near-instantaneous sequence of hormonal changes and physiological responses helps someone to fight the threat off or flee to safety.

What sleep loss does to the brain

Proteins in the brain perform various critical functions, such as helping neurotransmitters function or enabling electrical activity in the organ. These proteins must fold in specific ways to perform their duties, similar to paper airplanes. Sleep deprivation contributes to the gathering of misfolded proteins that aren't shaped correctly for their roles and so accumulate in undesired spaces, such as in the gaps between neurons.

Chemistry-informed advice for cooking pasta, including how to prevent clumping noodles

On a molecular level, pasta dough consists of protein structures that hold starch molecules, and the starches absorb water during cooking, forming a gel that softens the pasta. Pasta should not be rinsed after cooking. Instead, some of the pasta water should be added to the pasta sauce, as the gelatinous starch will help the sauce stick to the pasta.

HRT patches are popular partly because they have lower blood clotting risks than oral estradiol

Women taking estradiol for menopause or perimenopause are sometimes told oral HRT is not an option for them because it increases blood clot risks. But a large analysis in 2019 concluded that other forms of the HRT, such as the patch, creams, and gel, do not.

Menstruation, which occurs monthly, is the release of an unfertilized egg

This routine vaginal bleeding is part of a woman's hormonal cycle and occurs after an egg is released by an ovary during ovulation and isn't fertilized. Also known as periods, this monthly occurrence can cause symptoms including cramping, fatigue, and mood changes.

Accidental ingestion of batteries can be life-threatening

Tissue in the body can serve as a circuit path between the anode and cathode of a battery, resulting in electrical burns and gradual tissue erosion. Stomach acid can corrode a battery and cause its toxic contents to leak, making a person sick. Batteries for internal use, such as in pacemakers, require special designs.

Grip strength predicts death better than blood pressure

In a study covering about 140,000 people across 17 countries, scientists found that for every 5 kilogram drop in adults' grip strength, it raised the risk of death by 16%. Grip strength, the research found, was a stronger predictor of cardiovascular death than systolic blood pressure.

Visualize how CRISPR works at the molecular level

CRISPR is a revolutionary gene-editing technology already making a real-world impact in helping to treat several diseases and conditions. This simulation provides a microscopic view to help easily visualize the complex science.

Turbulence is needed to make airplanes more stable and golf balls fly farther

Vortex generators—small fins placed along airplane wings—create small eddies that prevent airflow separation, maintaining lift and preventing stalls. Golf balls have dimples that create a turbulent boundary layer on their surface, minimizing drag forces.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Tattoos remain visible on your skin thanks to immune cells called macrophages

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions